Typically, pulmonary artery catheters (PAC) are used in the evaluation of hemodynamic parameters like cardiac output. However, the insertion, operation and removal of such catheters requires highly skilled personnel. These catheters are relatively large devices having a diameter of 3 to 5 mm. In addition, the PAC is inserted via a central vein into the pulmonary artery and thus has a length of approximately 1.2 m to 1.5 m.
Due to the size and location of the PAC, there are significant complications and risks associated with their use. For example, cardiac arrhythmia's, incorrect placement and vascular damage may occur during insertion of the PAC. Infection endocarditis, pulmonary artery aneurysm, or rupture or embolism of catheter fragments may occur during maintenance of the catheter location. Further, knotting or shredding of the catheter, cardiac arrhythmia's or further vascular damage may occur during removal of the catheter. The benefits of procedure must be carefully weighed against the risks. In addition, the PAC may be inappropriate for use in certain patients including children.
Therefore, a need exists for a method and apparatus for determining hemodynamic and cardiac parameters without requiring a cardiac or pulmonary catheter. A need also exits for a catheter that can be readily employed in a broad spectrum of patient without creating undue risks.